As someone who has worked in the game industry for years both in AAA and indie, I’d say the switching costs are quite high and proportional to the team and code

As someone who has worked in the game industry for years both in AAA and indie, I’d say the switching costs are quite high and proportional to the team and code size. The reason it can be so challenging is a late change can easily double your preproduction time as you have to port over existing systems/tools/workflows and the bigger teams have many more of these systems. Usually this means bigger studios only changes engines at the start of new franchises or when fully rebooting old ones (For example, the new Mass Effect is porting from Frostbite to Unreal 5, but it’s only viable because it’s a super high budget reboot with new creative direction and the time to do it) It easier to switch if you’re indie, of course, but the reality is if your game is great it’s better to launch with the engine you have. And if your game is struggling gameplay-wise porting it to another engine isn’t going to help make the game better and puts the release at risk.